This invention relates to joint testers and grouting devices including combinations of such units. In particular this invention provides a conduit component through an expandable bladder enabling a communication passage to be maintained for testing or grouting the pipe joint.
The pipe joint pressurizing unit of this invention is devised to be inserted into a pipe such as a sewer pipe or other conduit having periodic joints. While the unit can be inserted into continuous pipes for repairing leaks, it is most suitable for pressure testing joints with air or water, and in one preferred embodiment, grouting the joint from inside the pipe and packing the grout.
Certain prior art devices have been utilized for testing and grouting pipes. For example, Stringham U.S. Pat. No. 3,103,235 issued Sept. 10, 1963 discloses a unit of the type proposed. As described therein a rigid cylindrical core has an outer surface where an elongated, expandable sleeve circled with bands along a middle section and at each end section, is circumferentially positioned. In use the device is located inside a pipe and positioned with its center section at a pipe joint. Each end section is expanded with compressed air sealing an annular center void. A grout from one or more supply lines is injected through the cylindrical core, sleeve and central band to fill the void and fill the joint. This packer, however, leaves a ring of grout on the inside of the pipe at the middle section.
In Zurbrigen et al, U.S. Pat. No. 3,168,909, issued Feb. 9, 1965 a device having a similar construction is provided with the means for elimination of the center band with only a small, washer-like plate holding the expandable sleeve against the rigid cylindrical core at the conduit end. As a result of grouting only a local pocket of grout remains. It is suggested this injection point may be blown clean by water after deflating the sleeve.
One construction for eliminating this pocket is provided in the device disclosed in Vanderlans, U.S. Pat. No. 4,421,698. Here the end of the conduit is connected to the surface of the expandable sleeve and moveably passes through the rigid cylindrical core. The conduit has a collar within the confines of the sleeve that has two annular, disk-like rubber diaphragms that attach to the sleeve and to the core. This double cuff arrangement enables displacement of the conduit through an oversized opening in the core, while maintaining a diaphragm seal of the conduit from the remainder of the air chamber that is formed between the sleeve and the core on inflation. This configuration may be subject to failure at the rubber diaphragms, a location difficult to repair.
The joint tester and grouting unit of this invention utilizes a simpler construction for the conduits that must pass through the inflatable and expandable sleeve to the zone between the pipe and the unit at the location of the pipe joint. The construction is simpler to repair and enables extremely high pressures to be used, while maintaining a seal with standard, easily replaceable, component elements.